<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>学生主页</title>
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css">
    <style>
        body {
            background-color: #f8f9fa;
            margin: 0;
            height: 100vh;
            display: flex;
            justify-content: center;
            align-items: center;
            font-family: Arial, sans-serif;
        }
        .container {
            width: 100%;
            max-width: 500px;
            background-color: white;
            padding: 30px;
            box-sizing: border-box;
            text-align: center;
            border-radius: 8px;
            box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
        }
        h1 {
            margin-bottom: 20px;
            font-weight: 300;
            color: #343a40;
            font-size: 1.8rem;
        }
        .form-group {
            margin-bottom: 20px;
        }
        .form-control {
            font-size: 1rem;
            padding: 10px;
            border-radius: 4px;
            border: 1px solid #ced4da;
        }
        .btn-primary {
            background-color: #007bff;
            color: white;
            border: none;
            border-radius: 4px;
            padding: 10px 20px;
            font-size: 1rem;
            width: 100%;
        }
        .btn-primary:hover {
            background-color: #0056b3;
        }
    </style>
</head>
<body>
    <div class="container">
        <h1>欢迎，学生 444!</h1>
        <form method="POST">
            <div class="form-group">
                <label for="class-name">输入要加入的班级名称:</label>
                <input type="text" id="class-name" name="class_name" class="form-control" value="10" required>
            </div>
            <button type="submit" class="btn btn-primary">加入班级</button>
        </form>
    </div>
</body>
</html>
